科尔沁沙质草地生物量对水、氮、磷添加的响应(英文)

为探寻科尔沁沙地东南部草地生产力自然恢复的主要限制因素,该文采用3因素2水平析因设计研究了水、氮、磷添加对沙质草地的影响。8种处理分别为添加水(W)、加氮肥(N)、加磷肥(P)、加水+氮肥(WN)、加水+磷肥(WP)、加氮肥+磷肥(NP)、加水+氮肥+磷肥(WNP)和对照(CK),每种处理6次重复,随机分配在48个4m×4m的样方中,样方之间留2m缓冲带。研究结果表明:科尔沁沙质草地生产力的恢复受氮素的限制,与水和磷无关;2005年生长季所有添加氮肥的样方,生物量和地上净初级生产力均较对照明显增加(P<0.05);禾本科根量在地下生物量中占优势。受限于地下生物量测定,目前的研究可能低估了我国北方草地的净初级生产力。     

Effects of mulching materials on nitrogen mineralization,nitrogen availability and poplar growth on degraded agricultural soil

Nitrogen (N) is usually the most limiting nutrient in degraded agricultural soils and affects the growth and ecological function of poplar (Populus spp.) plantations. We hypothesized that application of organic mulch would improve soil nitrogen availability and increase tree growth, while the quality of mulching materials would alter the supply of essential nutrients. In this study, poplar plantations were established in 2004 and two experiments were established in the field. The fresh above-ground biomass of cogongrass (Imperata cylindrica (L.) P. Beauv.), oak (Quercus fabri Hance), Chinese coriaria (Coriaria nepalensis Wallich) and brackenfern (Pteridium aquilinum (L.) Kuhn. var. latiusculum (Desv.) Underw. ex Heller) in the current year was selected as mulching materials, and mulches were annually applied at the rate of 5.0 kg/m² in the N mineralization experiment and 20,000 kg/ha in growth and nutrient availability experiment. Additions of fresh biomass significantly improved annual net N-mineralization estimates and the mulching treatments increased the cumulative N mineralized over the incubation period by 22–30%. However, a significant difference in the cumulative N mineralized was not observed among the mulched treatments, even if the cumulative N mineralized in the treatment mulched with oak (QF) was 5.9, 3.3 and 2.2% greater than that of treatments with brackenfern (PA), Chinese coriaria (CN) and cogongrass (IC), respectively. Application of fresh biomass mulch markedly affected soil available N contents and growth performance of poplar plantations. The mulching treatments with QF, IC, PA and CN increased annual means of available N concentration by 39.0, 29.0, 29.6 and 39.7% respectively. At the end of the fifth growing season, the average height of poplar plantations in treatments mulched with QF, IC, PA and CN was 46.8, 14.9, 42.6 and 57.4% greater than that in Check (CK-no mulch), while mean DBH increased by 35.4, 12.5, 33.3 and 52.1%, respectively. Overall, the productivity was enhanced in mulched plots at the end of the third growing season. Compared with CK, the treatments mulched with QF, IC, PA and CN increased total biomass by 97.4, 96.4, 63.1 and 81.6%, respectively. Based on the results of this study, annual application of 20,000 kg/ha fresh woody biomass would be recommended for soil improvement in young poplar plantations growing on a degraded agricultural soil.     

Effects of different concentrations of nitrogen and phosphorus on chlorophyll biosynthesis, chlorophyll a fluorescence, and photosynthesis in Larix olgensis seedlings

In our experiments, one-year-old Larix olgensis seedlings were cultivated in sand, and supplied with solutions with different concentrations of nitrate or phosphate. The effects of nitrogen and phosphorus supply on chlorophyll biosynthesis, total nitrogen content, and photosynthetic rate were studied. The experimental results are listed below: 1) 5-aminolevulinic acid (ALA) synthetic rate increased as nitrate concentrations supplied to larch seedlings increased from 1 to 8 mmol/L. But the rate decreased by 17% when nitrate concentration increased to 16 mmol/L, in contrast to the control. Under phosphate treatments, ALA synthetic rates were similar to those under nitrate treatments. The activities of porphobilinogen (PBG) synthase reached a maximum when larch seedlings were supplied with 8 mmol/L of nitrate or 1 mmol/L of phosphate. 2) when larch seedlings were supplied with 8 mmol/L of nitrate and 0.5 mmol/L of phosphate, the contents of chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids reached a maximum. The total nitrogen contents in leaves increased as nitrate concentrations increased. 3) When phosphate concentrations increased from 0.125 to 1 mmol/L, the total nitrogen contents in leaves slightly increased; however, continuous increase of phosphate concentrations resulted in the decrease in total nitrogen contents in leaves. When nitrate concentrations increased from 1 to 8 mmol/L, soluble protein contents in leaves increased in general, and continuous increase of nitrate concentrations induced a decrease in soluble protein contents in leaves. Under treatment of 0.25 mmol/L of phosphate, the soluble protein contents reached a maximum. 4) In general, F _v/F _m increased as nitrate concentrations increased from 1 to 8 mmol/L, and continuous increase of nitrate concentration resulted in decrease in F _v/F _m. The similar changes occurred under phosphate treatments. As nitrate concentrations increased from 1 to 8 mmol/L, photosynthetic rates gradually increased, but when nitrate concentrations increased to 16 mmol/L, photosynthetic rate reduced by 16%, in contrast to the control. Photosynthetic rates reached a maximum when seedlings were supplied with 1 mmol/L, and an oversupply of phosphate (2 mmol/L) resulted in decrease in photosynthetic rates. The results suggested that supply levels of nitrogen affected ALA biosynthetic rates, activities of PBG synthase, and affected contents of chlorophyll and carotenoids. Moreover, nitrogen supply levels affected contents of total nitrogen and soluble proteins in leaves, and net photosynthetic rates. ALA biosynthesis rates and activities of PBG synthase were affected by phosphate supply, but contents of chlorophyll and carotenoids were not affected. And net photosynthetic rates were affected little by phosphate supply. __________ Translated from Scientia Silvae Sinicae, 2005, 41(4) [译自:林业科学, 2005, 41(4)]     

氮磷配比对水曲柳光合作用的影响

以水曲柳2年生苗木作为试验材料,在人工气候室中用霍格兰水培营养液修改配方(四种氮、磷的不同配比,清水作为对照)进行水培试验,测定了叶片的光合作用、叶绿素荧光以及叶绿素含量等,以期从光合作用角度探讨不同配比的氮、磷对水曲柳幼苗生产力的影响。结果表明:不同氮、磷配比对水曲柳的多个光合指标差异影响显著。在一定范围内随着施磷量的逐渐增加净光合速率(Pn)升高;施磷肥对提高水曲柳叶片光合作用能力有积极作用;磷胁迫使叶绿素含量降低且对水曲柳叶片的碳同化和光能利用产生负影响。     

湘中丘陵区4种植被类型土壤全磷、有效磷含量的变异特征

为揭示中亚热带植被恢复对土壤磷(P)有效性的影响机制,在湘中丘陵区选取了地域毗邻、环境(土壤、气候)条件基本一致、处于不同植被恢复阶段的4种植物群落——檵木-南烛-杜鹃灌草丛(LVR)、檵木-杉木-白栎灌木林(LCQ)、马尾松-柯(又名石栎)-檵木针阔混交林(PLL)以及柯-红淡比-青冈常绿阔叶林(LAG)为研究对象,设置固定样地,按0～10、10～20,20～30,30～40 cm分层采集土壤样品,测定不同季节土壤全磷(TP)和有效磷(AP)含量,比较研究不同植被类型土壤TP、AP含量的差异及其季节变化特征。结果表明:1)不同植被类型同一土层TP含量在各季节总体上随着植被恢复而增加,且LAG与LCQ、LVR(除夏季外)差异显著;季节变化也基本一致,除LAG 0～10 cm土层外,均表现为"夏高冬低(或秋低)型"。2)不同植被类型同一季节同一土层AP含量夏、冬季差异较大,而春、秋季较小,不同植被类型同一土层AP含量在各季节的变化不完全随着植被恢复而逐渐增加;但同一土层AP的季节平均含量基本上随着植被恢复而增加,同一植被类型不同土层AP含量的季节变化不尽相同。3)土壤TP、AP含量与群落总生物量、地上部分生物量、根系生物量、凋落物层现存量、土壤粘粒百分含量、有机碳含量、全N含量呈极显著的正相关关系,与土壤pH值呈显著的负相关关系。4)不同植被类型群落生物量、土壤粘粒百分含量、有机碳含量、全N含量、pH值的差异显著影响土壤TP、AP的含量。     

丛枝菌根对油桐幼苗生长和氮磷吸收的影响

通过非灭菌土盆栽接种试验,观察了Glomus mosseae(GM)、G.intraradices(GI)、G.aggregatum(GA)和G.atunicatum(GE)4种AM真菌对油桐幼苗生长和氮磷吸收的影响,结果表明接种GM、GI和GE后菌根侵染率显著提高,侵染率分别为77.4%、92.3%和96.7%,比对照分别提高20.4%、43.5%、50.4%。接种GA与对照无显著差异;接种GM和GI后植株的干质量增加,而接种GA和GE对全株及各器官干质量影响不明显;接种4种真菌对油桐幼苗的氮素营养影响不大;接种GM、GI和GE显著提高了根部磷含量。综合考虑,接种GM效果最好。     

Biomass structure and nitrogen, phosphorus nutrient of Calamagrostis angustifolia populations in different communities of Sanjiang Plain, Northeast China

Calamagrostis angustifolia is the dominant species in the typical meadow and marsh meadow communities of Sanjiang Plain. The study on its biomass, the nitrogen (N) and phosphorus (P) contents in its different organs showed that the biomass of different C. angustifolia organs in the two types of wetland communities was distinctly different, which could be described by polynomial. The biomass of aboveground part and each organ presented single peak changing, with the maximum value of the latter occurred 15 days after. The F/C values were all less than 1, which were bigger in typical meadow than those in marsh meadow. The total N and P contents in different organs of aboveground part all descended monotonically in growth season, with the order of leaf>vagina>stem. The change of total N content in roots of the two types of C. angustifolia was consistent, while that of total P was quite different. The content of total N, ammonium nitrogen (NH₄ ⁺-N) and nitrate nitrogen (NO₃ ⁻-N), especially of NH₄ ⁺-N and NO₃ ⁻-N, varied widely in different organs, with NH₄ ⁺-N/NO₃ ⁻-N>1. Root was the important storage of N and P, but the storage of N and P in stem, leaf and vagina fluctuated greatly. The N/P ratios of the two types of C. angustifolia were all less than 14, which implied that N might be the limiting nutrient of C. angustifolia, and the limitation degree was higher in typical meadow than that in marsh meadow. __________ Translated from Chinese Journal of Applied Ecology, 2006, 17(2): 221–228 [译自: 应用生态学报]     

Effects of soil moisture and soil depth on nitrogen mineralization process under Mongolian pine plantations in Zhanggutai sandy land, P. R. China

选择章古台地区三块典型樟子松(Pinussylvestrisvar.mongolica)人工固沙林为研究对象,采用实验室好氧培养法测定了不同土壤层次和在不同水分条件下的N矿化过程。结果表明:土壤0-60cm层N净矿化速率垂直变化范围为1.06–7.52mg·kg-1·month-1;土壤层次和含水量及其交互作用对土壤N净矿化速率的影响均达到差异显著(P<0.05);净矿化速率随着土壤层次的加深而明显下降,0-15cm层占总净矿化量的60.52%;半饱和与饱和含水量处理差异不显著,但均高于不加水处理。为此,在半干旱地区必须进一步加强开展调控生态系统N矿化、循环及其收支平衡影响因素的研究。图1表4参20。     

不同土壤层次和土壤水分对章古台樟子松固沙林土壤N矿化过程的影响

选择章古台地区三块典型樟子松(Pinus sylvestris var. Mongolica)人工固沙林为研究对象,采用实验室好氧培养法测定了不同土壤层次和在不同水分条件下的N矿化过程.结果表明:土壤0-60 cm 层N净矿化速率垂直变化范围为1.06-7.52 mg·kg-1·month-1;土壤层次和含水量及其交互作用对土壤N净矿化速率的影响均达到差异显著(P<0.05);净矿化速率随着土壤层次的加深而明显下降,0-15 cm层占总净矿化量的60.52%;半饱和与饱和含水量处理差异不显著,但均高于不加水处理.为此,在半干旱地区必须进一步加强开展调控生态系统N矿化、循环及其收支平衡影响因素的研究.     

单叶蔓荆对滨海沙地土壤养分和木麻黄生长的影响

通过对比分析蔓荆地、非蔓荆地主要养分、木麻黄生长量及蔓荆林地小气候变化特点的试验研究表明 ,单叶蔓荆能促进木麻黄生长 ,可作为海滨沙地、风口地段固沙造林的先锋植被     

Long-term trends of phosphorus nutrition and topsoil phosphorus stocks in unfertilized and fertilized Scots pine (Pinus sylvestris) stands at two sites in Southern Germany

For two Scots pine (Pinus sylvestris) ecosystems in S Germany with different atmospheric N deposition (Pfaffenwinkel, intermediate N deposition; Pustert, large N deposition), the supply with phosphorus (P) has been monitored for unfertilized and fertilized plots over more than four decades by foliar analysis (1964–2007). Additionally, topsoil concentrations and stocks of total P and plant-available P (citric-acid-extractable phosphate) were quantified in 10-year intervals (1982/1984, 1994, 2004). At both sites, fertilization experiments, including the variants control, NPKMgCa + lime, PKMgCa + lime + introduction of lupine, corresponding to an addition of 75 and 90 kg ha⁻¹ P in Pustert and Pfaffenwinkel, respectively had been established in 1964. Our study revealed different trends of the P nutritional status for the pines at the two sites during the recent four decades: At Pustert, elevated atmospheric N deposition together with small topsoil P pools resulted in significant deterioration of Scots pine P nutrition and in an increasingly unbalanced N/P nutrition. At Pfaffenwinkel a trend of improved P nutrition from 1964 to 1991 was replaced by an opposite trend in the most recent 15 years. For our study sites, which are characterized by acidic soils with thick O layers, the forest floor stock of citric-acid-extractable phosphate showed a strong and significant correlation with the P concentration in current-year pine foliage, and thus was an appropriate variable to predict the P nutritional status of the stands. Total P stocks as well as the concentrations of total P in the forest floor or in the mineral topsoil were poorly correlated with pine foliar P concentrations and thus inappropriate predictors of P nutrition. P fertilization in the 1960s sustainably improved the P nutritional status of the stands. At Pfaffenwinkel, foliar P concentrations and topsoil stocks of citric-acid-extractable phosphate were increased at the fertilized plots relative to the control plots even 40 years after fertilization; at Pustert, foliar P concentrations were increased for about 20 years.     

Effects of adding water on seasonal variation of soil nitrogen availability under sandy grasslands in semi-arid region

Water is usally thought of a limiting factor for the restoration of semi-arid ecosystem. In the growing season of 2006, a study was conducted to determine the effects of modeling precipitation on seasonal patterns in concentrations of soil-available nitrogen and to describe the seasonal patterns in soil nitrogen availability and seasonal variation in the rates of net nitrogen mineralization of topsoil at Daqinggou ecological station in Keerqin sand lands, Inner Mongolia Autonomous Region, China. Manipulation of water （80 mm） was designed to be added to experiment plots of sandy grasslands in dry season. Water addition （W） treatment and control （CK） treatment were separately taken in six replications and randomly assigned in 12 plots （4 m×4 m for each） with 2-m buffers betweens. Results showed that the content of soil inorganic nitrogen and net nitrogen mineralization rate were not affected by adding water in sandy grassland of Keerqin sand lands. Net ni- trogen mineralization rates ranged from 0.5μg·g^-1,month^-1 to 4 μg.g^-1.month^-1. The highest values of soil inorganic nitrogen and net nitrogen mineralization occurred on October 15 in control plots. The seasonal changes of soil inorganic nitrogen contents exhibited ＂V＂ shape pattern that was related to seasonal patterns of soil ammonium-N （ascending trend） and nitrate-N transformation （descending trend）.     

添加水对半干旱区沙质草地土壤氮有效性季节变化的影响(英文)

Water is usally thought of a limiting factor for the restoration of semi-arid ecosystem. In the growing season of 2006, a study was conducted to determine the effects of modeling precipitation on seasonal patterns in concentrations of soil-available nitrogen and to describe the seasonal patterns in soil nitrogen availability and seasonal variation in the rates of net nitrogen mineralization of topsoil at Daqinggou ecological station in Keerqin sand lands, Inner Mongolia Autonomous Region, China. Manipulation of water (80 mm) was designed to be added to experiment plots of sandy grasslands in dry season. Water addition (W) treatment and control (CK) treatment were separately taken in six replications and randomly assigned in 12 plots (4 m×4 m for each) with 2-m buffers betweens. Results showed that the content of soil inorganic nitrogen and net nitrogen mineralization rate were not affected by adding water in sandy grassland of Keerqin sand lands. Net nitrogen mineralization rates ranged from 0.5 μg·g-1·month-1 to 4 μg·g-1·month-1. The highest values of soil inorganic nitrogen and net nitrogen mineralization occurred on October 15 in control plots. The seasonal changes of soil inorganic nitrogen contents exhibited "V" shape pattern that was related to seasonal patterns of soil ammonium-N (ascending trend) and nitrate-N transformation (descending trend).     

不同水生植物对富营养化水体氮磷的去除效果

从太湖选取水芹、石菖蒲、水葫芦、大薸、浮萍、荇菜、金鱼藻、黑藻、苦草、马来眼子菜作为研究对象,于2012年7月下旬开始在温室中利用水培法研究其对富营养化水体中氮磷的去除能力.试验结果表明,所选择的10种水生植物对污染水体均具有很好的净化效果且生长状况良好,其中水芹对总氮去除率最高,为91.50％,苦草对总磷的去除效果最好,去除率达94.20％.综合分析得出水生植物对水体氮、磷具有较强的吸收富集能力,总氮和总磷平均去除率均达到70％以上.     

Seasonality of mycorrhizal attributes,soil phosphorus and nitrogen of Juniperus phoenicea and Retama monosperma boiss. in an Atlantic sand dunes forest

Seasonal variation of mycorrhization attributes in a degraded ecosystem seems to be key information in conceiving rehabilitation programs that use mycorrhized plantations specific to that ecosystem. In order to record seasonality of arbuscular mycorrhizal fungi in an Atlantic sand dunes forest, root colonization and spores abundance alongside rhizospheric phosphorus and nitrogen of two plant species: Juniperus phoenicea and Retama monosperma, endemic to Essaouira sand dunes forest, were followed through three years. The findings were tested for statistical significance and correlated among each and to some meteorological variables: temperatures, precipitations, and humidity. Results showed that mycorrhization frequencies and intensities and spores densities changed seasonally. They had their peak at late winter-early spring and their low at summer. Phosphorus and nitrogen evolved significantly following seasons. Significant negative correlation was noted between phosphorus and mycorrhizal attributes evolution. Nitrogen correlated positively and significantly though weakly with R. monosperma mycorrhizal attributes. The correlations between mycorrhizal attributes and meteorological variables were not all evident except for temperatures and temperatures-precipitations combination, which had a direct negative impact on mycorrhizal attributes.     

Soil phosphorus fractions and their availability over natural succession from clear-cut of a mixed broadleaved and Korean pine forest in northeast ChinaOA

To assess phosphorus(P) status of forest soil under naturally restored vegetation, P fractions in the 10-cm soil layer were quantified at different successional stages on the clear-cut site of mixed broadleaved and Korean pine forest. Four communities of shrub, softwood broad-leaved forest, softwood and hardwood broad-leaved forest, and hardwood broad-leaved forest represented different successional stages. A soil sample from a primary broad-leaved and Korean pine stand was the control. A sequen...     

Interpretation and Compilation of Landsat TM Imagery for Land-use and Site Classification Mapping in the Korqin Sandy Lands, NE China

For the purpose of of forestation, planning and development in the Three-North Region, a series of 6 Landsat TM scenesfrom 1996 to 1997 were used to classify land-use conditions in the whole Korqin Sandy Lands at eastern part of Inner Mongolia, China, with an area of about 430×306 square kilometers. Later on, Site classiflcation was made and mapped for the 4 southern sandy counties. The annotation symbol for each agglomeration of site condition is comprised of six parts: land unit, land use pattern, soil texture, under ground water table, top-soil existence, wind erosion or salinisation condition. Field expedition and soil file augering help information extraction from the satellite imagery. The products include a land-use classiflcation map at scale 1/200,000 of the whole Korqin Sandy Lands, and a collection of site classiflcation maps at scale of 1/50,000, consisting of 135 pieces (42.8 cm×30.8 cm each). Electronic version of the maps is in raster form.     

Seasonal dynamics,especially autumnal retranslocation,of nitrogen and phosphorus in foliage of dominant and suppressed trees of beech,Fagus sylvatica

Seasonal changes in the N and P content of foliage in a young forest of Fagus sylvatica were measured. Leaves from branches of the upper and lower crown of dominant trees and from suppressed trees were compared. Nutrient retranslocation rates during senescence differed considerably between trees. This variation appeared not to be related to any differences in environmental factors or tree vigour, and was probably genetically induced. In dominant trees the most efficient retranslocation of N was recorded in the upper crown and probably resulted from higher leaf temperatures and a longer senescent period in the sun leaves than in the shade leaves. Phosphorus retranslocation efficiency was higher in suppressed trees than in dominant ones, but no such tendency was observed with N. The most obvious difference between leaves at different crown levels concerned the time at which P translocation began; an outflow of P from leaves in the lower crown began in June, while in the upper crown this outflow did not begin until September/October.     

干旱半干旱沙区人工植被与土壤水分环境相互作用关系研究进展

土壤水分在干旱、半干旱沙区人工植被恢复、植物生长和群落演替过程中起着重要作用。文中综述了我国主要沙化地区人工固沙植被土壤水分状况和动态的研究现状, 分析了土壤水分的时空格局及其影响因子; 探讨植被冠层、生物结皮、植物根系对土壤水分的调控作用和影响机理以及干旱、半干旱沙区人工植被土壤水分空间异质性及相关问题; 最后提出人工植被区的土壤水分动态模拟预测、土壤—植被—大气系统水量平衡和水分循环以及空间尺度扩展等问题应是未来的研究重点。     

Photosynthesis in relation to leaf nitrogen, phosphorus and specific leaf area of seedlings and saplings in tropical montane rain forests of Hainan Island, south China

In order to make clear the relationships between photosynthesis and leaf N, leaf P and SLA of tropical trees, and test the differences in the relationships among life-form groups (trees, shrub-like trees and shrubs), seedlings and saplings of 101 species from a tropical montane rain forest, located in the Diaoluo Mountain of Hainan Island, were selected. The net photosynthesis based on area and mass (A _area and A _mass), leaf nitrogen content based on area and mass (N _area and N _mass), leaf phosphorus content based on area and mass (P _area and P _mass) and specific leaf area (SLA) were measured and/or calculated. The results showed that A _area and A _mass tended to follow the order of shrubs > trees > shrub-like trees. One-way ANOVA showed that the difference in A _area between shrubs and shrub-like trees was significant (p<0.05), and for A _mass there were significant differences between shrubs and shrub-like trees and between shrubs and tree species (p<0.05). The relationships between A _area and N _mass were highly significant in all three life-form groups and for all species (p<0.0001). The correlation between A _area and P _mass was highly significant in shrubs (p = 0.0038), shrub-like trees (p < 0.0002) and for all species (p<0.0001), but not significant in trees (p>0.05). The relationship between A _area and SLAwas highly significant in shrubs (p = 0.0006), trees (p<0.0001) and for all species (p<0.0001), however this relation was not significant in shrub-like trees (p>0.05). The relationships between A _mass and leaf N and SLA were highly significant in all three life-form groups and for all species (p<0.0001). For A _mass and leaf P, there were significant correlations in tree groups (p = 0.0377) and highly significant correlations in shrub groups (p = 0.0004), shrub-like tree groups (p = 0.0018) and for all species (p < 0.0001). Stepwise regression showed that predicted A _mass values were closer to the observed values than those for predicted A _area values. Thus, it can be concluded that the relationships obtained from seedling and sapling measurements are close to those from mature individuals; correlations between photosynthesis and N _mass, P _mass and SLA traits are significant and the relationships are stronger and more stable for A _mass than for A _area. __________ Translated from Acta Ecologica Sinica, 2007, 27(11): 4651–4661 [译自:生态学报]